How i can send a gift?

You can only buy it right now and send it now, buying something on sale to keep and store, not longer possible.
If there a price difference is too big (USA to EUR) often no longer possible, why you want to create region giveaways.

You have to add the winner to your friendlist or send to their emailadress which you will get when they win.

You can also look into the thrid party stores that offer steam gift links or keys, like HumbleBundle, GreenmanGaming, Amazon, Fanatical, GamersGate and others.

I see, thanks.

Or add the winner afterwards and buy the game as a gift then. Be careful if you are trying to use discounts (on sales e.g.) though, because the winner is allowed to redeem the gift within 7 days.

First thing you do is not post your question in the "Deals" section of Steamgifts.com js

Would be better asked in General, Uncatagorized or Off-Topic

I agree with NB264.
No reason to buy from Steam anymore unless they have the "best" current sale.
I'm a big fan of Humble Bundle, Fanatical (use to be Bundle Stars), Indie Gala & DailyIndie Games.
I use other sites too, but these are my top 4.

I primarily use this "Deals" discussion and www.istheranydeal.com to game price shop.

Thanks. And what happen if the winner redeem the gift?

Thanks.

Click the 'Reply' underneath a comment to reply directly to it. This notifies the commenter that you have replied to them.
To change details about your thread, click the green 'Open' in the top right. This can be used to change the category of the thread from Deals to General.

You can use do a google search against the title of the game you're thinking of giving away, adding "steamdb" to the google search, and then click on the game's steamdb page that google gives you as a search response. By comparing the percentages in the converted price column [you can change the default currency using the dropbox in the top right corner], note the regions on that page which list the game for a price of more than 10% over your currency's value. Those regions are the ones you will be unable to gift to, and should exclude from your giveaway.

If you are in South America, you can likely not send Steam gifts to most of the users here. So keys would be a better option than anything from the Steam Store.

If you are Spanish, that does not apply.

if you're region locked, don't waste time with the steam store. get keys from resellers like humble bundle or wingamestore, it's easier to make giveaways.